Posted By: wyldebill
weight difference 8 3/4, 9 in and d60 - 03/03/15 06:35 PM
has any body ever sat down and compaired the weights side by side? ive seen all the bickering about what is stonger. i just wondering about a weight dif.
weight difference 8 3/4, 9 in and d60
Posted By: Locomotion
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 06:48 PM
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
It's been discussed and, for some reason, 30 - 40 lbs sticks in my mind. But it will have to be an apples-to-apples comparison with the same width, spool or sure-grip, etc.
It's been discussed and, for some reason, 30 - 40 lbs sticks in my mind. But it will have to be an apples-to-apples comparison with the same width, spool or sure-grip, etc.
Posted By: moparguy7074
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 06:50 PM
Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
Oh the humanity! 
LOL
Posted By: dogdays
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 06:58 PM
It's a simple fact, the farther the pinion centerline is away from the ring gear centerline, as a percentage, the lower the mechanical efficiency. That's because there is more sliding of surfaces.
These are called hypoid gears. The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind. Before his invention, those right angle gear drives had the pinion centerline and ring gear centerline intersecting.
The hypoid gearset allowed car manufacturers to lower the driveshaft, thus lower the floor of the car.
Hypoid gearsets mandated the development of Extreme Pressure (EP or GL-5) gear lubes to deal with the sliding surfaces.
R.
These are called hypoid gears. The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind. Before his invention, those right angle gear drives had the pinion centerline and ring gear centerline intersecting.
The hypoid gearset allowed car manufacturers to lower the driveshaft, thus lower the floor of the car.
Hypoid gearsets mandated the development of Extreme Pressure (EP or GL-5) gear lubes to deal with the sliding surfaces.
R.
Posted By: 68shifter
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 07:04 PM
A complete dana 60 with posi, 11" drums, 35 spline axles and a body width that I shipped weighed 212lbs. This was complete with brake lines etc.
No idea on the other two.
No idea on the other two.
Posted By: Locomotion
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 07:06 PM
Quote:Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
It would be pointless to argue with the facts.
As far as strength, I'm well aware of my old buddy Quicktree's opinion on 9" vs Dana 60's. But despite the ease of gear changes in a 9", a Dana 60 will handle anything most people would ever need. Once the optimum gear ratio is known, the drop-out center benefit isn't that big of a deal. Besides, the expense of maxing out a 9" is astronomical.
Posted By: moparniac
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 07:08 PM
My Dana 60 was lighter than the 83/4 it replaced ...the danA had a spool and disc brakes.
Posted By: 1Fast340
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 08:25 PM
Quote:Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
Dont we need the pinionangle variable to be perfectly sure?
Posted By: wyldebill
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 09:08 PM
i didnt start this to argue witch is best. only asking for weights. i dont thing the parasitic drag is enough to worry with.
Posted By: beecrazy
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 09:39 PM
According to this article in Hot rod its 17lbs without brakes.
W/O BRAKES W/BRAKES
12-bolt 171 210
Strange S60 191 230
Currie 9-inch 174 238
http://www.hotrod.com/how-to/transmission-drivetrain/ccrp-0806-chevy-chevelle-rear-axle-swap/
Kevin
W/O BRAKES W/BRAKES
12-bolt 171 210
Strange S60 191 230
Currie 9-inch 174 238
http://www.hotrod.com/how-to/transmission-drivetrain/ccrp-0806-chevy-chevelle-rear-axle-swap/
Kevin
Posted By: perfmachst
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 09:49 PM
hi, my dana 60 with 35 spline axles and spool was 32 # more versus 8 3/4 with same parts. did not slow car one bit. actually rolled easier.
Posted By: AndyF
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 09:52 PM
It is going to depend on what parts are used. Spools are very light compared to a locker or limited slip. Big axles are heavier than small axles. Standard gears or lightweight gears? Aluminum center section or iron? No brakes, drum brakes, disc brakes?
Posted By: 1Fast340
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 10:25 PM
Quote:
i didnt start this to argue witch is best. only asking for weights. i dont thing the parasitic drag is enough to worry with.
Sorry could not resist.
To get back on track i think you could see a substantial difference depending on all the parts inside the axle aswell as other little things here and there all the way down to details like the driveshaft lenght,wish will be different depending on rearend used
Posted By: 451Cuda
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 11:10 PM
Quote:
has any body ever sat down and compaired the weights side by side? ive seen all the bickering about what is stonger. i just wondering about a weight dif.
I wish they'd been a bit more scientific about this comparison, but it gives a good idea of the differences in weight.
http://www.hotrod.com/how-to/transmission-drivetrain/ccrp-0806-chevy-chevelle-rear-axle-swap/
Posted By: Quicktree
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 11:18 PM
Quote:dana 60's are for trucks 9s are for racing, you can't argue factsQuote:Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
It would be pointless to argue with the facts.
As far as strength, I'm well aware of my old buddy Quicktree's opinion on 9" vs Dana 60's. But despite the ease of gear changes in a 9", a Dana 60 will handle anything most people would ever need. Once the optimum gear ratio is known, the drop-out center benefit isn't that big of a deal. Besides, the expense of maxing out a 9" is astronomical.
Posted By: BradH
Re: weight difference 8 3/4, 9 in and d60 - 03/03/15 11:20 PM
Quote:
My Dana 60 was lighter than the 83/4 it replaced ...the danA had a spool and disc brakes.
My Strange S-60 is going to lighten my wallet a whole lot more than the 8-3/4 it's going to replace.
Posted By: Locomotion
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 12:40 AM
Quote:Quote:dana 60's are for trucks 9s are for racing, you can't argue factsQuote:Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
It would be pointless to argue with the facts.
As far as strength, I'm well aware of my old buddy Quicktree's opinion on 9" vs Dana 60's. But despite the ease of gear changes in a 9", a Dana 60 will handle anything most people would ever need. Once the optimum gear ratio is known, the drop-out center benefit isn't that big of a deal. Besides, the expense of maxing out a 9" is astronomical.
A wider gear selection and the simplicity of a drop-out center section are THE ONLY benefits a 9" has over a Dana 60. Pros and a small percentage of hard core sportsman racers will benefit from a 9". Spend enough money and you can make just about anything stronger/lighter/faster than another competitive part.
But back on topic....
If rear end weight is a concern, most likely to go faster, then efficiency should also be a concern. If you install a heavier, but stronger and less expensive rear and don't slow down, it's worth it! If a Dana 60 will result in similar ET's over an 8 3/4", then it will certainly be faster than a Ford 9" which is heavier and even less efficient than an 8 3/4".
Posted By: 1967dartgt
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 12:48 AM
Quote:Quote:Quote:dana 60's are for trucks 9s are for racing, you can't argue factsQuote:Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
It would be pointless to argue with the facts.
As far as strength, I'm well aware of my old buddy Quicktree's opinion on 9" vs Dana 60's. But despite the ease of gear changes in a 9", a Dana 60 will handle anything most people would ever need. Once the optimum gear ratio is known, the drop-out center benefit isn't that big of a deal. Besides, the expense of maxing out a 9" is astronomical.
A wider gear selection and the simplicity of a drop-out center section are THE ONLY benefits a 9" has over a Dana 60. Pros and a small percentage of hard core sportsman racers will benefit from a 9". Spend enough money and you can make just about anything stronger/lighter/faster than another competitive part.
But back on topic....
If rear end weight is a concern, most likely to go faster, then efficiency should also be a concern. If you install a heavier, but stronger and less expensive rear and don't slow down, it's worth it! If a Dana 60 will result in similar ET's over an 8 3/4", then it will certainly be faster than a Ford 9" which is heavier and even less efficient than an 8 3/4".
So your not considering the double bearing on pinion, aluminum center section, the avaibilty of chromoly housings, bolt through main caps and the ability to back brace benefits? Weird I would consider all of them pluses.
Posted By: wyldebill
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 12:54 AM
sorry i asked. 
Posted By: MR_P_BODY
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 01:02 AM
Quote:
sorry i asked.
Bee Crazy gave you some decent numbers.. but even Hot Rod
said he brakes on the 9" were VERY heavy being they
were the LARGE drums
W/O BRAKES W/BRAKES
12-bolt 171 210
Strange S60 191 230
Currie 9-inch 174 238
Posted By: justinp61
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 01:07 AM
Quote:
sorry i asked.
Call Dr Diff and get some apples to apples numbers.
Posted By: dvw
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 01:19 AM
My 44" wide Dana, w/ladder bar brackets, Strange steel spool, 35 spline axles w/3" studs, 4.10 gear set, chrome steel cover, and yoke was 165Lbs.
Doug
Doug
Posted By: MattW
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 01:25 AM
Quote:
sorry i asked.
Don McCallum 68 hemi barracuda tested all three rears in the pursuit of the very last hp and et.
Guess what, nothing changed. All where the same et and MPH.
Pick your poison.
The Dana will get you were you need to go so would the 9. Each has its place.
Posted By: Quicktree
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 03:19 AM
Quote:you just saved me some typingQuote:Quote:Quote:dana 60's are for trucks 9s are for racing, you can't argue factsQuote:Quote:
FYI, while there are obvious weight differences, the Dana 60 is more "efficient" than an 8 3/4 rear. I've been told by several class racers that in most cases, there has been minimal, if any, change in ET. The Ford 9" is probably the least efficient of the popular rears and the Chevy 12 bolt is the best!
Are you trying to start WW III? Saying a 9" is the least efficient!
It would be pointless to argue with the facts.
As far as strength, I'm well aware of my old buddy Quicktree's opinion on 9" vs Dana 60's. But despite the ease of gear changes in a 9", a Dana 60 will handle anything most people would ever need. Once the optimum gear ratio is known, the drop-out center benefit isn't that big of a deal. Besides, the expense of maxing out a 9" is astronomical.
A wider gear selection and the simplicity of a drop-out center section are THE ONLY benefits a 9" has over a Dana 60. Pros and a small percentage of hard core sportsman racers will benefit from a 9". Spend enough money and you can make just about anything stronger/lighter/faster than another competitive part.
But back on topic....
If rear end weight is a concern, most likely to go faster, then efficiency should also be a concern. If you install a heavier, but stronger and less expensive rear and don't slow down, it's worth it! If a Dana 60 will result in similar ET's over an 8 3/4", then it will certainly be faster than a Ford 9" which is heavier and even less efficient than an 8 3/4".
So your not considering the double bearing on pinion, aluminum center section, the avaibilty of chromoly housings, bolt through main caps and the ability to back brace benefits? Weird I would consider all of them pluses.
Posted By: dvw
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 03:35 AM
So your not considering the double bearing on pinion, aluminum center section, the avaibilty of chromoly housings, bolt through main caps and the ability to back brace benefits? Weird I would consider all of them pluses. (quote)
Can I find those in the junk yard?
Doug
Can I find those in the junk yard?
Doug
Posted By: Quicktree
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 03:38 AM
Quote:can you find your motor in a junk yard? but yes you can if you can find a nodular 9". I found one once for $200 slapped a mini spool in it and beat on it for years.you can find plenty of dana's just go to the dump truck section..
So your not considering the double bearing on pinion, aluminum center section, the avaibilty of chromoly housings, bolt through main caps and the ability to back brace benefits? Weird I would consider all of them pluses. (quote)
Can I find those in the junk yard?
Doug
Posted By: dvw
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 04:24 AM
Quote:Quote:can you find your motor in a junk yard? but yes you can if you can find a nodular 9". I found one once for $200 slapped a mini spool in it and beat on it for years.you can find plenty of dana's just go to the dump truck section..
So your not considering the double bearing on pinion, aluminum center section, the avaibilty of chromoly housings, bolt through main caps and the ability to back brace benefits? Weird I would consider all of them pluses. (quote)
Can I find those in the junk yard?
Doug
That's where I got it. Actually out of a Ford E300.
Posted By: W.I.N. Racing
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 04:30 AM
Quote:
It's a simple fact, the farther the pinion centerline is away from the ring gear centerline, as a percentage, the lower the mechanical efficiency. That's because there is more sliding of surfaces.
These are called hypoid gears. The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind. Before his invention, those right angle gear drives had the pinion centerline and ring gear centerline intersecting.
The hypoid gearset allowed car manufacturers to lower the driveshaft, thus lower the floor of the car.
Hypoid gearsets mandated the development of Extreme Pressure (EP or GL-5) gear lubes to deal with the sliding surfaces.
R.
Someone has done their home work
Bonus question; who and where was the Hypoid invented???
Posted By: Pacnorthcuda
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 04:50 AM
Quote:Quote:
It's a simple fact, the farther the pinion centerline is away from the ring gear centerline, as a percentage, the lower the mechanical efficiency. That's because there is more sliding of surfaces.
These are called hypoid gears. The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind. Before his invention, those right angle gear drives had the pinion centerline and ring gear centerline intersecting.
The hypoid gearset allowed car manufacturers to lower the driveshaft, thus lower the floor of the car.
Hypoid gearsets mandated the development of Extreme Pressure (EP or GL-5) gear lubes to deal with the sliding surfaces.
R.
Someone has done their home work
Bonus question; who and where was the Hypoid invented???
Tesla. Another factoid is that the lower the pinion to the ring relationship the stronger (think Ford 9") simply because of greater tooth to tooth contact. Also why is less efficient in terms of drag. A trade off.
Posted By: jcc
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 05:20 AM
Quote:
The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind.
Thank God for smart people.
Of course we are assuming the first one worked.
Posted By: 1967dartgt
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 05:22 AM
Quote:
So your not considering the double bearing on pinion, aluminum center section, the avaibilty of chromoly housings, bolt through main caps and the ability to back brace benefits? Weird I would consider all of them pluses. (quote)
Can I find those in the junk yard?
Doug
Sorry don't shop for race car parts in junkyard. Wouldn't trust them at 160+ mph.
Posted By: W.I.N. Racing
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 05:59 AM
Quote:
Someone has done their home work
Bonus question; who and where was the Hypoid invented???
Tesla. Another factoid is that the lower the pinion to the ring relationship the stronger (think Ford 9") simply because of greater tooth to tooth contact. Also why is less efficient in terms of drag. A trade off.
You are incorrect sir... both accounts. The first Hypoid ring and pinion was invented by a trio of companies and patented in 1935. Ford motor company, Shell oil and The Gleason Works.
As for the 9" being stronger due to its pinion off set, one of the contributors to its weakness is its pinion offset. The fact that the crown is engaged by the pinion almost under the crown center line creates crown deflection due to the vector forces alignment with regard to the ears of the carrier bearing journals (limited to no lateral support). Meaning the vector forces are trying to push the crown and pinion away from each other deflecting the carrier bearing journals (one reason for draw thru cap bolts)and ahead of the rear pinion bearing. The reason for this potential deflection is the further the force generation from the bulk of the casting the greater the deflection will be (BTW the 8 3/4 has similar issues). Un-like the 12 bolt and Dana where the force is generated directly between the caps and over the rear pinion bearing. This brings me to the fact that a 9" needs a crown support to keep the crown from folding over in high HP apps as well, another feature (this time from ford)is the rear pinion bearing to bolster the 9" strength for everyday use, with out it. the pinion head simply pops off.
You are correct that more tooth engagement typically relates to a stronger gear set due to less tooth deformation but the gear on the 9" does not suffer from tooth deformation it suffers from system deformation.
Posted By: MR_P_BODY
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 06:30 AM
Quote:Quote:
It's a simple fact, the farther the pinion centerline is away from the ring gear centerline, as a percentage, the lower the mechanical efficiency. That's because there is more sliding of surfaces.
These are called hypoid gears. The inventor of the hypoid gear actually worked out the mathematics of the surfaces before building the first one. That flat boggles my mind. Before his invention, those right angle gear drives had the pinion centerline and ring gear centerline intersecting.
The hypoid gearset allowed car manufacturers to lower the driveshaft, thus lower the floor of the car.
Hypoid gearsets mandated the development of Extreme Pressure (EP or GL-5) gear lubes to deal with the sliding surfaces.
R.
Someone has done their home work
Bonus question; who and where was the Hypoid invented???
Spicer invented it
EDIT
Maybe I'm wrong but I believe it was Spicer who made
the first ones... but I found this as well
Mr. Trbojevich’s most notable work that brought him international recognition was the invention of the Hypoid gear. First published in 1923, it was a new type of spiral bevel gear employing previously unexploited mathematical techniques. The Hypoid gear is used on the great majority of all cars, trucks and military vehicles today. Together with his invention of the tools and machines necessary for its manufacture, the Hypoid gear became an integral part of the final drive mechanism of automobiles by 1931. Its effect was immediately apparent in that the overall height of rear-drive passenger automobiles was reduced by at least four inches.
But I also read that Packard was putting the Hypoid
gear in their cars in 1918
Posted By: SportF
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 06:48 PM
Rear end opinions have now graduated to the top of my 3 favorite Moparts topics, along with cone sure grips, and silicon brake fluid.
As a note:
Hypoid gears are cut on a hypoidal curve.
ALL gears, under load, try to force each other apart. This is what makes a sure grip work.
As a note:
Hypoid gears are cut on a hypoidal curve.
ALL gears, under load, try to force each other apart. This is what makes a sure grip work.
Posted By: BradH
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 07:20 PM
Quote:
... cone sure grips...
OK, from my experience... JUNK.
"Your results may vary".
Posted By: Cudajon
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 09:06 PM
Trained Egyptians on a gear hobber in Cairo Egypt. You cut the gears in a "soft" steal and then send it to a hardening process. Also a further surface hardening. These were used in the M60 and M1 tanks. Fascinating process with lots of math. How's that for getting Off Topic. 
Posted By: Wv68charger
Re: weight difference 8 3/4, 9 in and d60 - 03/04/15 10:15 PM
Quote:
Rear end opinions have now graduated to the top of my 3 favorite Moparts topics, along with cone sure grips, and silicon brake fluid.
As a note:
Hypoid gears are cut on a hypoidal curve.
ALL gears, under load, try to force each other apart. This is what makes a sure grip work.
Don't forget pinion angle!
Posted By: fishy340
Re: weight difference 8 3/4, 9 in and d60 - 03/05/15 04:35 AM
I have everyone mentioned in this thread and NOTHING weighs as much as a Dana center section.
My 8 3/4 weighs within a lb or 2 of the 9" I bought however my 9" is braced,has 3.5" tubes w gun drilled 40 spline axles and a beautiful strange MW looking aluminum center section.
My 8 3/4 weighs within a lb or 2 of the 9" I bought however my 9" is braced,has 3.5" tubes w gun drilled 40 spline axles and a beautiful strange MW looking aluminum center section.
Posted By: skrews
Re: weight difference 8 3/4, 9 in and d60 - 03/05/15 09:17 AM
Just swapped out my A body 8 3/4 for a stock spec S60. Dana had the non finned drums , 8 3/4 had the finned drums. Weight difference was about 26 lbs. Both had spools.
Posted By: SportF
Re: weight difference 8 3/4, 9 in and d60 - 03/05/15 05:19 PM
I'm with you Fishy, those 9" aluminum center sections look great!
Posted By: W.I.N. Racing
Re: weight difference 8 3/4, 9 in and d60 - 03/06/15 04:36 AM
Quote:
You are incorrect sir... both accounts. The first Hypoid ring and pinion was invented by a trio of companies and patented in 1935. Ford motor company, Shell oil and The Gleason Works.
As for the 9" being stronger due to its pinion off set, one of the contributors to its weakness is its pinion offset. The fact that the crown is engaged by the pinion almost under the crown center line creates crown deflection due to the vector forces alignment with regard to the ears of the carrier bearing journals (limited to no lateral support). Meaning the vector forces are trying to push the crown and pinion away from each other deflecting the carrier bearing journals (one reason for draw thru cap bolts)and ahead of the rear pinion bearing. The reason for this potential deflection is the further the force generation from the bulk of the casting the greater the deflection will be (BTW the 8 3/4 has similar issues). Un-like the 12 bolt and Dana where the force is generated directly between the caps and over the rear pinion bearing. This brings me to the fact that a 9" needs a crown support to keep the crown from folding over in high HP apps as well, another feature (this time from ford)is the rear pinion bearing to bolster the 9" strength for everyday use, with out it. the pinion head simply pops off.
You are correct that more tooth engagement typically relates to a stronger gear set due to less tooth deformation but the gear on the 9" does not suffer from tooth deformation it suffers from system deformation.
Pardon my mistake ...the Hypoid gear was introduced by the Gleason works in 1925
not 1935...BTW The very first Hypoid pinion has been in my hot little hands (about 10 yrs ago)when I worked for Gleasons.I believe people confuse a Hypoid for a Spirial Bevel
Posted By: Moparmal
Re: weight difference 8 3/4, 9 in and d60 - 03/06/15 09:38 AM
Thx Dogdays and WIN for the interesting background on hypoid gears and third member deficiencies.
Ive had a few 'debates' over the desirability of the various types with a few 'gurus' in Oz........the blind faith in the 9" is pretty hard to shake..
.....but the up sides of parts availability for the 9" isnt the whole story...quite clearly.....
Ive had a few 'debates' over the desirability of the various types with a few 'gurus' in Oz........the blind faith in the 9" is pretty hard to shake..
.....but the up sides of parts availability for the 9" isnt the whole story...quite clearly.....
Posted By: 68roadrunner
Re: weight difference 8 3/4, 9 in and d60 - 03/06/15 05:04 PM
here is where i weighed some last winter
https://board.moparts.org/ubbthreads/show...rue#Post8061019
https://board.moparts.org/ubbthreads/show...rue#Post8061019
Posted By: DavidDean
Re: weight difference 8 3/4, 9 in and d60 - 03/07/15 02:13 AM
I recently changed from an 8 3/4" to a Dana. I think there was about 40 lbs difference. I thought it would slow down a bit its actually a bit quicker in the 1/8 maybe .05.07. I don't think it was the dana as I kept working on the chassis (pre load and shock adjustment).
